<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        //单引号和双引号都可以表示字符串， 但是左右引号一定要匹配
        let str1 = "sldkfjl";
        let str2 = 'slkjsladkjf';

        // \xnn:以十六进制代码nn表示一个字符 \x41表示A
        let str3 = " my name is : \x41"; //my name is : A
        alert(str3.length);


        let lang = "Java";
        lang = lang + "Script";
        alert(lang)

    </script>


</head>
<body>

</body>
</html>